During the period 1976 to 1978 I was consumed with discovering and creating new mechanisms that moved a simple wheel back and forth. The interesting part of the sculpture was how the mechanism worked.

1979 marked a turning point. I had developed a sufficient understanding of mechanism design. The new challenge was to use that knowledge to produce pieces with more complex and unpredictable motion. The sculptures from 1979 clearly mark this change in design direction.

Kaleidoscope is the first sculpture I designed to create an optical moiré pattern. To give the viewer time to recognize the moiré pattern, the wheels had to counter rotate for several revolutions at the same rate of speed. To give the eye a rest and to create a second pattern, the wheels had to slowly stop and then reverse direction. The drive mechanism to do this was totally new but it was based on a concept I learned in making the 1976 sculpture Anticipation.

Serpentine is my first completely unpredictable sculpture. (I can't say "random" because technically a machine can't produce truly random motion. I learned that on the Internet!) The patterning part is a powered double pendulum. I had played with this type of motion in some of my first hand driven kinetic toys but figuring out a mechanism to drive the motion was a challenge. The wheels had to be free to rotate most of the time with just an occasional push when they started to slow down. None of my prior mechanisms could do this so I had to design something completely new.

Blizzard is an attempt to produce unpredictable optical pattern sequences. I was looking for a melding of the optical pattern idea in Kaleidoscope with the unpredictable nature of Serpentine. My solution was to drive each wheel with its own mechanism that runs at a slightly different speed.

I continued designing patterning sculpures with desending weights for several more years. It wasn't motion that inspired the next shift but a change in power source.